Ergonomics in the Laboratory

Transcription

1 instrumentation [management/administration and training generalist] Ergonomics in the Laboratory Terry Jo Gile, MT(ASCP)MA Ed From Gile and Associates, St Louis, MO Ergonomic disorders Work-site analysis Workplace design Administrative controls Musculoskeletal disorders such as carpal tunnel syndrome and lower back pain constitute the most important cause of work-related absence due to illness and occupational disability. These conditions can be attributed in part to poor design of equipment, technical systems, and tasks. The reporting of musculoskeletal disorders and other work-related disorders attributable to ergonomic hazards has increased significantly in the laboratory. Transcriptionists, phlebotomists, and histotechnologists are most prone to musculoskeletal disorders due to the repetitive nature of their work. Ergonomic Disorders Although there are a variety of ergonomic disorders, the most common are carpal tunnel syndrome and back disorders. Carpal tunnel syndrome causes tingling, numbness, or severe pain in the wrist and hand as well as reduced strength in the hand. If the pressure on the median nerve of the hand persists, it can cause permanent loss of sensation and even partial paralysis. People often do not associate their pain with work because symptoms may occur only during nonwork hours. According to the National Safety Council, back disorders account for 31% of all musculoskeletal disorders and are frequently caused by faulty body mechanics such as poor posture; bending and reaching; and carrying, moving, or lifting loads that are too heavy or too big. 1 Keeping the body in a neutral position with the work close to the body is helpful in maintaining proper posture. Additionally, distributing rest time throughout the day can reduce muscle fatigue. For example, the musculoskeletal system benefits more from a 5-minute break every hour than it does from a 15- minute break every 4 hours. Work-Site Analysis The first step in evaluating an ergonomic disorder is a work-site analysis to determine what jobs and workstations are the sources of the greatest problems. Each workstation that is considered a problem or high risk should be analyzed by direct observation with assistance from qualified personnel such as an ergonomist, a health-care provider, or an affected employee. Use of a symptom On March 6, 2001, marking the first time the Congressional Review Act had been used to repeal a federal regulation, Senate Resolution 6 to rescind the Occupational Safety and Health Administration (OSHA) Ergonomic Standard was passed, and on March 7, 2001, House Resolution 79 to rescind OSHA s Ergonomic Standard was also passed. President Bush signed these resolutions into law on Tuesday, March 20, OSHA s Ergonomic Standard was issued shortly before former President Clinton left office; the list of regulations that formed the standard were aimed at preventing carpal tunnel syndrome, tendinitis, and other kinds of repetitive stress disorders. Although some insiders believe that in rescinding the standard, Congress is stopping OSHA from protecting Americans against repetitive stress disorders, others believe that the newly appointed Secretary of Labor, Elaine Chao, will instead take this opportunity to revamp the Ergonomic Standard. The process of revamping the standard could include revisiting some research that may be outdated and clarifying the impact of the standard on small business through an economic impact statement. 263

2 your lab focus Employee name Date Job name or work station Shift Hours worked/week Time on this job Have you had any pain or discomfort during the last year? Check areas: Neck Shoulder Elbow/forearm Hand/wrist Fingers Upper back Lower back Thigh/knee Lower leg Ankle/foot Put a check by the word(s) that best describe your problem: Aching Burning Cramping Loss of color Numbness ( asleep ) Pain Swelling Stiffness Tingling Weakness Other When did you first notice the problem? How long does each episode last? What do you think caused the problem? Have you had this problem in the last 7 days? Have you had medical treatment for this problem? If no, why not? If yes, where did you receive treatment? Did the treatment help? How many days have you taken off work in the last year because of this problem? days Please comment on what you think would improve your symptoms. 264 [F1] Ergonomic symptoms survey checklist. survey checklist [F1] may also be useful, as may be a workstation checklist [F2]. All risk factors within an area should be identified and proper controls implemented to eliminate them. The idea of an ergonomic approach is to make incremental improvements to reduce or eliminate some, if not all, risk factors. Workplace Design Where feasible, hazards can be prevented by effective workplace design. Engineering controls are the preferred means of controlling or reducing ergonomic hazards in the workplace. In 1998, the National Committee for Clinical Laboratory Standards published a new standard on laboratory design, which is

3 your lab focus 1. Does the work space allow for a full range of work movements? 2. Are mechanical aids and equipment provided where feasible? 3. Is the work surface height proper and adjustable? 4. Can the work surface be tilted or angled if necessary? 5. Is the work station designed to minimize or eliminate: twisting at the waist? reaching above the shoulder? bending at the waist? extension of the arms? bending or twisting of the wrist? elevation of elbows? 6. Do employees have the option of varying their posture? 7. Are the employees hands or arms subjected to pressure from sharp edges on work surfaces? 8. Is an armrest provided where needed? 9. Is a footrest provided where needed? 10. Is the floor surface irregular, slippery, or sloping? 11. Are cushioned floor mats provided for workers who are required to stand for long periods? 12. Where chairs or stools are provided, are they easily adjustable and suited to the task? 13. Is the workplace temperature too hot or too cold? 14. Are all task requirements visible from comfortable positions? 15. Is there a preventive maintenance program for mechanical aids, tools, and other equipment? [F2] Is your workstation body-friendly? helpful to anyone involved in remodeling or designing new space. 2 It includes information on the amount of space required by men and women sitting, standing, and in a wheelchair. A workstation should be designed so that it accommodates the specific worker who uses it, not just the average worker. The height of tables and chairs should be adjustable to provide proper back and leg support. Workstations should allow sufficient space for the knees and feet. When seated, the width clearance must be at least 27 inches and the depth clearance must be at least 18 inches at the knees and 45 inches at the feet for sufficient comfort. Key Terms Ergonomist: One who studies how work stations can be adapted to the people who use them. Carpal tunnel syndrome: The compression and entrapment of the median nerve where it passes through the wrist into the hand in the carpal tunnel. Musculoskeletal disorders: Musculoskeletal and nervous system disorders that may be caused or aggravated by repetitive motions, forceful exertions, vibration, mechanical compression, sustained or awkward postures, or exposure to noise over extended periods. Examples include carpal tunnel syndrome, trigger finger, tendinitis, herniated spinal disk, tension neck syndrome, rotator cuff syndrome, sciatica, lower back pain, carpet layer s knee, and handarm vibration syndrome. Computer keyboards should be adjusted so that they are near or below elbow level with the mouse on the same plane as the keyboard. Modular furniture that can be adjusted for employee height is beneficial. An adjustment range allowing for at least 11 inches of height differential is recommended to allow for individual differences in body height. Proper seating should be made available to employees whenever possible. The backrest should support the lower back and tilt to allow for some movement while working. Employees should be made aware that wallets or items in back pockets may cause the hips to tilt, straining the muscles in the back as well as the hips and spine. The shoulders should be relaxed to allow a neutral position with the forearm at a 90-degree angle to ensure good circulation. The chair should have a padded seat with the proper width and depth to allow the knees to bend at 90 degrees with the feet flat on the floor or on a footrest. This will ensure proper circulation. 265

4 your lab focus 266 [F3] An ergonomically correct computer workstation. Chairs used in the laboratory on tile floors should have 5 legs, soft casters, and no arms, and they should be made of material that can be cleaned and disinfected easily (eg, vinyl). Hard casters may be used for nonbiohazard areas with carpet. Footrests help reduce stress and fatigue for shorter employees. To determine the type of footrest necessary, measurement should be taken with the employee sitting with the knees bent at a 90-degree angle. The distance from the bottom of the shoe to the floor is the height of the footrest needed. When working with a computer monitor, the eyes should be at least 23 to 29 inches away from the monitor, depending on the individual s focal length (ie, the distance at which the eyes can clearly see the image) and the size of the monitor [F3]. Tilting the monitor, using an antiglare screen on the monitor, or adjusting the overhead lights can reduce glare. Also, every 15 minutes, the employee should look away from the monitor and focus on something else to help rest the eyes. The head should be straight or tilted downward slightly. The topmost line of the display screen should never be higher than eye level. The document holder should be directly next to the display screen to minimize eye, neck, and back movement. Administrative Controls Administrative controls reduce the duration, frequency, and severity of exposure to ergonomic hazards. Examples include job rotation to allow use of different muscle-tendon groups, frequent breaks to reduce stress and strain, and increasing the number of employees assigned to a task where work conditions are severe. Some facilities have initiated exercise periods for employees at the beginning of and throughout a shift to prevent injuries and to promote wellness. In addition, a preventive maintenance program for equipment to verify proper working order is essential. An effective housekeeping program to minimize slippery work surfaces and related hazards such as slips and falls due to clutter is essential. In one case, a facility reduced its workers compensation claims by $90,000 in just 1 year by implementing workstation redesign. Medical management can help to eliminate or reduce the risk of ergonomically related problems and symptoms through early identification and treatment. Sedentary jobs restrict blood circulation, preventing muscles from getting the nutrients they need and eliminating waste products such as lactic acid. Ironically, lack of movement can provoke the same joint injuries that afflict athletes. For example, bending over a keyboard all day puts pressure on the tendons of the shoulder, which can lead to a torn rotator cuff in later years. Slumping puts pressure on the lower spine, and sitting still and crossing one s legs causes edema of the lower extremities. This swelling then prompts the heart to work harder and blood pressure to rise. Training and education go a long way toward increasing ergonomic awareness. Training enables supervisors and employees to understand the hazards associated with a job, their prevention and control, and their medical consequences. Suggestions and input from workers who are educated about ergonomic hazards can be very helpful in designing improved work practices to reduce those hazards. A good ergonomics education and training program will teach employees how to use equipment properly and the correct way to do a variety of job tasks.

5 your lab focus Helping to identify habits such as arching the neck while wearing bifocals so that one can peer at a computer screen through the lower lenses and cradling the telephone between the head and shoulder rather than using a headset or telephone rest to alleviate ergonomic stresses is helpful. Photographs or videos of employees at their work station before and after evaluation and adjustment are visual tools that can be used for training as well. After employees are trained in a particular task, supervisors should ensure that work practice controls are maintained by monitoring employees; improper practices should be promptly corrected to prevent injury. Such monitoring can become a part of the laboratory s quality assurance program. Careful attention to proper workstation set up can reduce workers compensation claims and increase productivity in the laboratory. 1. National Safety Council. Available at: Accessed March 20, Painter PC, Belanger AC, Blank CH, et al. Laboratory Design: Approved Guideline. Wayne, PA: NCCLS; NCCLS publication GP18-A. Suggested Readings Gile TJ. Ergonomics for the laboratory. Clin Lab Manage Rev. 1994;8:5-18. Gile TJ. The body friendly workstation [brochure]. St Louis, MO: Gile and Associates; US Department of Labor, Occupational Safety and Health Administration. Ergonomic safety and health program management guidelines. 54 Federal Register 3904 (1989) (codified at 29 CFR 1910). 267